Firing rate control mechanism for automatic firearms



A. GAZDA May 1.7, 1949.

FIRING RATE CONTROL MECHANISM FOR AUTOMATIC FIREARMS 3 Sheets-Sheet lFiled June 27, 41944 Gttomeg May 17,1949. A. GAZDA 2,470,158

FIRING vRATE CONTROL MECHANISM FOR AUTOMATIC FIREARMS Filed June 27,1944' 3 Sheets-Sheet 2 Miri. Y

'Juventor ,VfG/szw? Gttomeg May 17, 1949.. A. GAZDA' i 2,470,158

FIRING RATE CONTROL MECHANISM FOR AUTOMATIC FIREARMS Filed June 27, 1944s Smelts-she@t 5 WQ/,Q

@2f C "06 O /Jzj 2J. O J9 i i Le 4 i 3g n /'c s 72 I7 l k [tlf/y i jinventor i (ttorneg Patented May 17, 1949 FIRING RATE ,CONTROL MECHANISMFOR vAU'IOMATIC, FIREARMS AntoinelGazd'a), Provldence1t..

'The -present Yinventicm relates Atoa Anew and improved recoil. and`return spring- 'mechanism vfor the breech "block an `automaticYfirearm; more especially vak rearm ofthe so-called blowiback" type,wherein the-breech block is forced rearwardly bythe' explosion of *the'charge in the cartridge against the inertia of" the per-ts and therecoilvv Lzin-d returnl springx mechanism; the relationship of" 'theparts being suchl Ithat the rearwardy movement of' the-ibreech-blockeffects a, tensioning of the springs off' `the spring mechanism wherebytheblbck is returned' 'for firing thenext shot.

A- -pri-rmauy-cbject -of the` present invention kis the realizationosimplebut effective Yineensaesociatedl'with and constitutingvpa-r-t yofthe-said spring mechanism, whereby the rate yoftltlerearmfmaybereadilyregulated.

A further obect of the invention is the reali'- 'zati'o-n of e simplebuteiectivemeansfsssociat-ed withend constituting partei said springfain-ism; whereby: the recoii force of lthe latter may beregule-tecl.

Torithese ends, briey stated, meansisprovided whereby 'thev .mass of therotary porfis of" the spring mechanism: may :be xcentroliedly varied,and additional means is `omvided .for regn'lably controlling theinitial. tension orv preloadwoflzhe springmechanism.

Additional; objectsamd I:idimititiafges of. thepites.- .ent innention`will `appear from. .the following detailed! description, ofpresently-pixeferredf il instinctive' embodiments :thereof, referencebeing made in this regard to the accompanyingsheets fofdrewing wherein:

Fig. 1-, is a topplan View oflthe reafrm', with showninilongitudinallsectiom;

Fig, 2 is a top= plan view. ofk the rear portion of, the firearm-en arelatively'enlangedgfscale, parts beingshown inflon g-itudinal sectionFig. -4 is a fragmentary sectional view showing the spring mechanismunloaded mounted in ceasing .ofv modified form; f

Fig. 5v :is e View cor-.responding to Fig. 4. but showing. the springmechanism as pre-loadedg Fig., -6v is a1 sectional. View through loneform fof iywfheel mass and- Fig. '7- isa sectional view throughenotherform. c-ywheelmass.

The fireznrny .comprises the usuel barrel M1, breechzftube H, and:.breech block l2 reciprocably :nonni/.e121 the breech tube;y 11|. Thereturn sind recoil sonnig.y ineclninismL Vconwrises two..housings 2Ywixedton opposite sides, as 'viewed from the top, of the tube lf, eachcontaining a. toothed lcumulus It rotatablyfmonnted on a studl5-adjustably vsecured"tfof-its housing- 153, as 'hereinafter described.'Each toothed annulus lll/is Iin mesh with one of' two gear racks .w onthe .breech .block l2 through slots inthe -tube 'l-l. InsideAeach:airmulus' -llf `ris arranged a spiral spring I9, theyinner end ofwhich: Ais attached7 "to the respective .studl I5' and Vthe` outer 'endof .which is secured to the annulus I4. The spiral springs rections andtend to move the breech block f1.2 4forfwerollytoward the :barrel llffby rmeims` of `the two toothedemnnliy 4 4;,

When lus-ing; the reajrm according; to thef'in.- vention, the breech:block; l-2`r .is drawn. back` in they usuel manner untilit is looked .bya conventional. `:trigger-frelealsdbie locking.VV device (not shown)which holds: fit in. its rear loadingA posi@- .tion l'ig.. 2f). During:this, movement of. the breech. fhlock t2; intoy ythe .loading position,both .spiral springs Sfere tensioned. JSimultaf-neously e kcaattridgefrom the oamtridge magazine (not shown) isr introduced` lin front ofbreech 4bloei: 12:. When the aboveementionedf locking: device isreleased, the 4'broers-ltr `block L2 is movedv forward by the 'twospirali' springs I9 whereby .the vvcartridge'is moved into. thelcadingchamber tto he red immediately thereafter. The 'block i12 is againlforced back against the -actionoff the two'spiralf springs |9 .by thepressure of vthe gases lresulting from the explosion, whereupon` ttheLabo-ue: describeds `ringA action. is repeated. In Aorder to. :damp :therecoil of the breech. block 1.2,@ -builer in ythe fomr ci a. helicalspring,l -20 nir-the likemayzbe provided.,

lhreededly .or other-wise suitably secured to eachv .an-nulus M .on.eachy side thereof .is a 'discylike cover plete 2l .or .22, interposed.between the `central flange `23 of which and the stud` l5 areantifnictionbearingsld.. The cover plates, .21. `and 22f are .ofdiiierent configuration and weight `and thusseverelly constitute e.varableflywheel mass which makes it possible to. regulate the ring 4reteof the .by .the simple expedient of changingrtherespective cover plates21,22. The two ilywheel .masses 2 I Vand .22 which have been illustratedare solely exemplary in .character :a plural-ity Aof .such masses,v ofvarying magnitude, man? be provided. Two similar messes 2l maybe @usedon each vk,snm-ilus M, or the lett-,er may be associated `withtwcdissimiler masses as shown.

Keyed 15o-ooeendofI each stud l5 .is clever-25,

free end.: of lwilnlcl'i carries 'ai springfpressed plunger 26 adaptedto be received in any one of a plurality of recesses 21 provided in thecasing I3. Knob 28 is provided for withdrawing the plunger 26 from arecess and, after rotating the lever 25 to correspondingly tension orpre-load the spring I9, for re-inserting the same in the recess 21corresponding to the pre-load position. The other end of each stud Icarries a cap I1 secured hereto by pin I1', as shown. When the plunger26 is in the rst recess 21, there is no preload. Fig. 4 shows the springI9 without pre-load, while Fig. 5 shows the spring in a pre-tensioned orpreloaded state.

A modiiied form of casing |30, is shown invFigs.

4 and 5, the recesses 21 being formed in an outwardly projecting ange29. In any event, re-

cesses 21 are concentrically arranged lwith respect y to stud I5. Infiring the rst round, the breech block l2 is, of course, drawn backagainst the action of the springs I9. Stud I5 is, in eiect, a xedabutment as long as plunger 26 remains in engagement with any recess 21in the housing I3.

The possibility of effecting the pre-loading of the springs I9 makes itpossible to regulate the recoil force with the different firing ratesobtained through the different flywheel masses, and thus to realize theobjects of the invention.

The present application is in part a continuation of abandoned copendingapplication, Serial No. 289,661, filed August 11, 1939, for Automaticfirearms.

Having thus disclosed the invention, what is claimed is:

1. In an automatic firearm, a barrel, a breech tube secured to saidbarrel, a breech block slidable in said breech tube, a pair of spiralrecoil springs, a rack upon said breech block associated with eachspring, a gear cooperating with each rack having one end of theassociated recoil spring Xed thereto, a casing for each gear andassociated spring xed to said tube, a plate detachably connected to saidgear whereby said plate may be replaced by another plate of differentmass to vary the ring rate of the iirearrn,

a xable abutment extending axially through said gear to which the otherend of each spring is connected, a lever connected to said abutment andmeans for connecting said lever selectively at any one of a plurality ofspaced points upon said casing to vary the initial tension of theassociated recoil spring.

2. In an automatic firearm, a barrel, a breech tube secured to saidbarrel, a breech block slidable in said breech tube, a spiral recoilspring located upon each side of said breech block, a rack upon saidbreech block associated with each spring, a gear cooperating with eachrack, a casingenclosing each gear and associated spring fixed to saidtube, each spring being connected to the gear associated therewith andto said casing, and a pair of plates anti-frictionally mounted andthreadedly connected to eachgear whereby said plates may be replaced byother plates of different mass thereby varying the ring rate of saidrearm.

3. In an automatic rearm, a barrel, a breech tube secured to saidbarrel, a breech block slidable in said breech tube, a pair of spiralrecoil springs located upon opposite sides of said breech block, a xableabutment associated with" each spring to which one end of the associatedspring is connected, a gear also associated with each spring to whichthe other end of said spring is connected, a pair of racks on saidbreech block adjacent said springs and cooperating with said 4 gearswhereby the breech block is always urged in a forward direction and therecoil is diffused through said springs, means xed to said breech tubeand completely encasing each spring and associated abutment and gear, adetachable weight rotatably mounted on said abutment and secured to eachgear whereby different weights may be attached to each gear to vary thefiring rate, a lever connected to said abutment and means connectingsaid lever selectively to any one of a plurality of spaced points uponsaid encasingmeans to vary the positioning of said abutment and therebythe initial tension of the associated recoil spring.

4. In an automatic firearm, a barrel, a breech tube securedto saidbarrel, a breech block slidable in said breech tube, a pair of spiralrecoil springs located at opposite sides of said breech block, anannular exteriorly toothed gear associated with each of said springshaving one end of the spring associated therewith secured thereto, racksupon said breech block cooperating with said gears, a casing fixed tosaid breech tube for each spring and associated gear, an abutmentmounted in said casing to which the other end of each associated springis secured and detachable cover plates rotatably mountedon said abutmentsecured to each annular gear enclosing the spring associated therewithwhereby said cover plates may be detached and replaced with cover platesof different mass to vary the firing rate.

5. In an automatic rearm, a barrel, a breech tube secured to saidbarrel, a breech block slidable in said breech tube, a pair of spiralrecoil springs located at opposite sides of said breech block, anannular exteriorly toothed gear associated with each of said springshaving one end of the spring associated therewith secured thereto, racksupon said breech block cooperating with said gears, a casing iixed tosaid breech tube for each spring and associated gear, `an abutmentmounted in said casing to which the other end of each associated springis secured, detachable cover plates rotatably mounted on said abutmentsecured to each annular gear whereby said cover plates may be detachedand replaced with cover plates of diierent mass to vary the firing rate,a lever xed at one end to said abutment, a spring actuated plungermounted at the other end of said lever and said casing having aplurality of spaced apertures with which said plunger cooperates to xsaid abutment in a plurality of positions to vary the initial tension ofsaid recoil springs.

6. In an automatic rearm, a barrel, a breech tube secured to saidbarrel, a breech block slidable in said breech tube, a pair of spiralrecoil springs located at opposite sides of said breech block, anannular exteriorly toothed gear associated with each of said springshaving one end of the spring associated therewith secured thereto, racksupon said breech block cooperating with said gears, a casing xed to saidbreech tube for each spring and associated gear, an abutment mounted insaid casing to which the other end of each associated spring is secured,detachable cover plates rotatably mounted on said abutment secured toeach annular gear whereby said cover plates may be detached and replacedwith cover plates of different mass to vary the firing rate, a leverfixed at one end to said abutment, a spring actuated plunger mounted atthe other end of said lever, said casing having a plurality ol? spacedapertures with which said plunger coopcrates to nx said abutment in aplurality of posi- 5 tions rto vary the initial tension of said recoilNumber springs and anti-friction means located between 547,027 saidplates and said abutment. 1,142,896 ANTOINE GAZDA. 1,164,250 5 1,292,267REFERENCESA CITED 1,361,937 The following references are of record inthe le of this patent: N b

UNITED STATES PATENTS 10 unegg Number Name Date 125.706

319,596 Maxim June 9, 1885 Name v Date Oehrle Oct. 1, 1895 Lewis June15, 1915 Auero Jan. 21, 1915 Dawson et al Jan. 21, 1919 Philips June '7,1932 FOREIGN PATENTS Country Date Austria June 10, 1922 Great BritainApr. 10, 1919

